The phrase 'show a negative trend' is correct and can be used in written English.
You could use it to describe a situation where something has decreased or declined in a negative way. For example, "Sales figures in recent months have shown a negative trend, with a decrease of 10%."
Silica, aluminium, sodium and potassium show a negative trend in ultramafic rocks.
The results show a negative trend for the compositional effect when a region specializes in manufacturing, particularly for the chemical, chemical textile, and pulp and paper sectors, and the iron and steel, non-ferrous metal, and cement and ceramics sectors.
Especially in Greece the raw data that we used in this research show a negative trend in the transport activity of the main port of the country, Piraeus [11].
Both lines show a negative trend in exam performance for increasing test anxiety.
Both sets of radon levels show a negative trend but those with the pre-defined levels are less marked.
Severity of hypoglycemia was also not significantly associated with visuospatial performance but did show a negative trend (Table 3).
The landscapes that showed a negative trend were those situated near the security settlements.
The hourly trend for C4 is different from every other cluster and EDS as it shows a negative trend.
The chemically impregnated AC, AC3 (Fig. 5a, b) and AC4 (Fig. 6a, b) showed a negative trend of porosity development.
The second axis showed a negative trend with wetness index, direct duration and aspect, and a positive trend with sediment index and slope.
As a result, the shrubby grassland, grassland, and bareland showed a negative trend, whereas the woodland, bushland, cultivated, and settlements showed a positive trend (Table 3).
